scheduler: Stream formation events before service registration
scheduler: Stream formation events before service registration

Since streaming formation events can error (e.g. by not getting a
current event within the timeout), and this happens before the loop
begins, this can leave a cluster without any active schedulers.

Signed-off-by: Lewis Marshall <748e1641a368164906d4a0c0e3965345453dcc93@lmars.net>

philiplb/flynn,flynn/flynn,philiplb/flynn,flynn/flynn,flynn/flynn,philiplb/flynn,lmars/flynn,lmars/flynn,lmars/flynn,lmars/flynn,philiplb/flynn,philiplb/flynn,lmars/flynn,flynn/flynn,flynn/flynn